Chair bottoms



Pl'l 15, 1957 1.J. BOND ETAL 2,788,845

CHAIR BoTToMs Filed Sept. l, 1955 A Tranne v5 United lStates PatenfQ CHAIR BOTTOMS John J. Bond and Robert J. Bond, Milwaukee, Wis., assignors to Bond, Inc., a corporation of Wisconsin Application September 1, 1955, Serial No. 532,032

6 Claims. (Cl. 155-179) This invention relates to improvements in chair bottoms.

More particularly stated, the invention relates to an arrangement of spring members and spring supports in a chair bottom whereby to provide not only adequate support for the weight of the occupant of the chair, but also to provide satisfactory softness to suit the wide range of weights of persons who may occupy the chair.

The chair bottom of this invention includes two principle assemblies. One comprises a oating platform for support of a seat cushion and the other comprises a set of tension springs to give a new characteristic action to the floating platform.

The invention is further adapted to the type of furniture which may be made in knocked-down units for assembly at point of retail sale.

In the drawings:

Fig. 1 is a vertical section through a chair bottom em bodying the invention taken along the line 2-2 of Fig. 2.

Fig. 2 is a plan view of the chair bottom.

Fig. 3 is an enlarged vertical section on line 3--3 of Fig. 2.

The chair bottom in accord with this invention is adaptable for manufacture in a box frame made up of front and back board-like members 11 and 12 and two side members 13 and 14 which are cut away as shown most clearly in Fig. 1 at 15 to provide ample room for free action of the iloating portion of the spring construction to be described below.

In a particular example of the invention shown in the drawings, an angle iron 16 is secured to the inner face of member 11 and is provided with spaced openings 17 through which hooked portions of zigzag springs 18 may be inserted. At the rear of the box frame a similar angle iron 19 is secured to the inner face of member 12. This angle iron 19 is likewise provided with spaced openings 20 to receive the hooked ends of tension springs 21. These tension springs have approximately a three inch stretch, and their forward ends are in hooked engagement respectively with the hooked rearward ends of the zigzag springs 18.

The zigzag springs 18 are of a type described in reissued Patent No. 21,263, reissued November 14, 1939, to Karl Kaden. They are made of hard spring wire and normally assume an upwardly bowed contour as shown in Pig. 1. They are tension-compression springs and are hooked in tandem with the tension springs 21.

Secured to a loop of the zigzag springs 18 at points adjacent the front ends of the springs is a hard wire frame 25 preferably made of a No. 9 or a No. 10 size wire for usual sizes of chairs and settees. The frame 25 is clipped to one of the forward convolutions of each of the zigzag springs 18 by clips 24. The frame 25 is of such dimensions as to encompass approximately the area which would comprise the forward one-half of the seat cushion area of the chair bottom. The rearward onehalf of the area of the seat bottom is framed by a separate 2,788,845 Patented Apr. 16, 1957 ,lice

2 hard wire frame 26 which is secured to one of the loops of each of the zigzag springs adjacent the rear ends thereof by clips 27 as shown in Fig. 2.

The two frames 25 andv 26 are of such dimensions that their respective adjacent members 28 and 29 are clipped by clips 30 and 31 respectively to adjacent convolutions of the zigzag springs 18 as shown most clearly in Figs. i and 2.

To finish the chair, suitable legs 32, suitable separately assemblable back 33, a cushion 34, and friction pad 35 may be supplemented by suitable buffer strips 36, as shown in Fig. 1.

In the particular chair bottom shown and intended to be acceptable for heavy adults, the wire of which the zigzag springs 18 is formed is a No. 9 wire and is designated to assume the arc shown in Fig. 1 when under tension of tension springs 21 which are designated for a tension of pounds. The angle iron 16 is 1%" below the top margin of the member 11. The angle iron 19 is 11/2 below the top margin of the box member 12. This provides an average satisfactory pitch from front to rear of the spring members 18 and frames 25 and 26. The pitch may be changed to provide the particular seating position desired.

Spring members 18 and frames 25 and 26 comprise a floating spring bottom under control of the tension springs 21 with a resulting chair bottom action which is completely novel and is very satisfactory from the point of view of comfort and from the point of view of a long life of the chair bottom and the upholstery which rests thereon. It will be noted that the wire frames 25 and 26 extend laterally into the open space provided by the relief of the side members at 15, see Figs. 2 and 3.

The action is novel in the following sense: That the zigzag springs provide a comparatively soft seat throughout a considerable vertical motion at the time that a weight is placed upon the wire framed portion. The natural upward arc of the zigzag springs is fairly readily overcome, but since the springs 18 as described in said Patent Re. 21,263 act, when arched downwardly, in tandem with the tension springs 21 to pick up the entire load which is impressed upon them and the spring bottom goes down as a multi-framed unit to satisfactorily support even extreme weights which may be placed thereon. Of course, if and when the hard wire frame side members bear upon the box side members 13 and 14, a semi-positive support is added to assist the tension springs in their supporting duties.

While the array of zigzag springs extends over an area equivalent to one chair bottom, the hard wire frames isolate portions of the array in such manner as to cause the portions of zigzag springs within each frame to reinforce and stiffen each other within the frame.

We claim:

l. A chair bottom including a box frame, upwardly and rearwardly arched spring members extending rearwardly from the front of the box frame, spring members being laterally curved in zigzag configuration and terminating rearwardly in a spring connection, tension springs respectively connected to said arched springs at their rearward spring connections and disposed rearwardly into connection with the rear portion of the bof-a frame.

2. The chair bottom of claim i wherein a hard wire frame of approximately the width of the box frame is clipped to the arched springs whereby to force the arched springs to move in unison.

3. The chair bottom of claim l wherein a pair of hard wire frames each of approximately the width of the box frame is clipped to the arched springs whereby to force. the arched springs to move in unison, the adjacent sides hard wire frames y'being parallel with each other Y clipped to the convolutions of said zigzag springs wherealong the peak of the arches of the zigzag springs:

4. The chair bottom of claim 1 wherein a hard wire frame ofapproximately th'eswidth of the boxmframeris Lclippedto the arched springs whereby to force the ,arched springs to move in'unison, saidbox frames having side members, thetupper portions of which are Vrelievecland ciently to overlie the relieved portions of said side members of the box frame. y Y

5. ln a spring bottom for upholstered furniture, a box frame, a plurality of zigzag springs connected to thebox -the hard wireV frameis VYextende'dlaterally at least sui- -frame and having compression-tension laterally disposed il,

convolutions, said springs providing Van areav approximately corresponding to the area of the bottom, and a by to isolate the spring action of portions of' said area.

6. A chair bottom including a box frame, upwardly and rearwardly arched spring members extending rear-l References Cited in the le of this patent UNITED STATES PATENTS Kronheim Q YJuly 29, 1946 

